Advanced Layering System and Design for the Increased Thermal Protection of Wildland Fire Shelters

The last line of defense for wildland firefighters is their emergency fire shelter. These shelters consist of a multilayer outer dome composed of an aluminum foil laminated to a woven silica fabric and an aluminum foil laminated to a woven fiberglass fabric. Wildland fires are extremely variable and can change direction and intensity at any point. If a wildland firefighter gets caught in an entrapment scenario, they are trained to deploy their shelter, get inside, lie on the ground, and allow the fire to burn over them. Research being performed at the Textile Protection and Comfort Center aims to create lightweight shelter materials and layering structures that better protect wildland firefighters in these conditions. This project aims to improve the thermal protective performance of the shelter materials through the incorporation of convective heat blockers and insulative battings. Foils of various metals, including aluminum and copper, were used as the convective blockers, and ceramic nonwoven fabrics were used as insulative batting. Layering concepts have been tested using a single Meker burner apparatus to expose the samples to combined radiant and convective heat. The results from the bench-level testing identified materials that offer the most protection per weight. Layering designs that incorporated convective blockers and inorganic nonwovens outperformed the control due to the additional layers of thermal protection and the added air layers. The most promising designs will be made into prototype shelters and will undergo full-scale testing in both the PyroMan fire test chamber and in live fire field scenarios.